Data storage systems can comprise a central processing unit (CPU), one or more disc controllers and a plurality of disc drives. Computer program code operating on the CPU and/or disc controllers controls the manner in which user data is stored and accessed on the disc drives. User data can be stored in various data storage formats, such as redundant array of independent drive (RAID) formats, for example. Multiple RAID formats can be concurrently employed within the data storage system. The optimal RAID format employed for particular data files can reflect the importance of the data and the frequency of access or update. Data that is easily accessed from other sources or otherwise reacquired can be stored in a non fault-tolerant format such a RAID 0, for example. Data that is stored in a fault tolerant format that is accessed frequently can be stored in a RAID 1 format. Data stored in a fault tolerant format that is accessed less frequently can be stored in a RAID 5 format. Alternatively RAID 5 can be employed to provide greater storage capacity as compared to RAID 1. Data such as financial data or system configuration data can be stored in a RAID 6 or Raid 1×3 format that provides greater redundancy than RAID-1 or RAID-5. As such, there can exist the need for a plurality of data storage formats to be concurrently supported within the system storage capacity. Also, it can be advantageous to change dynamically from a first storage format to a second storage format. For example, RAID 1 can be advantageously employed to update daily billing records, and then converted to RAID 5 format for archival storage. The rate at which storage can be dynamically allocated and the efficiency of utilization of available storage capacity significantly affects the marketability and profit margin of a data storage system.